Automatic Power-On Alarms on Cellphones

Update 03/11/2015 Some LG Models (420g) also have this feature

One night I didn’t want my cell phone alarm to ring in the morning, but I was too tired to go through the menu and turn it off, so instead I just shut down my phone. Imagine my surprise when the alarm rang in the morning anyway!

At first I thought that maybe this was due to the fact that the
charger was plugged in, so the phone was partially awake in charging
mode and therefore had access to the alarm. So I repeated the experiment
with the charger unplugged, and, lo and behold, the alarm sounded again
in the morning.

That’s when I finally looked up the options in the alarm menu and noticed the auto-turn on option! I suppose I could have looked up the info online, but it really didn’t click in my head that the phone could turn itself on.

One of the searches I did online after the fact, compared it to expecting your toaster to plug itself back in after you’ve unplugged it, which is kind of how I looked at it.

However, it turns out that these Samsung Tracfone handsets pictured
above are not the only phones to have had this feature. Apparently a
couple of old Blackberry phones had this feature as well.

How useful is this? Well, if you’re traveling and
want to avoid getting calls at night or want to save on the battery life, but
still need an alarm to wake you up or remind you of an appointment, this is the
perfect feature.

So Which Phones Have Auto Power On Alarms?

As far as I can tell, among the feature phones, only the “S” series from Samsung have this feature. I have verified that the Samsung S425G and the S275G have this, and,
presumably, the S390G. The older phones from the “R” series, such as the R355C and
the “T” series such as the T404G do not have this feature

I also checked other manufacturer handsets that have been tested and reviewed here, and I didn’t
find this feature on any phones by LG or Motorola.

NOTE: It has been pointed out to me (thanks Richard), that the LG 420g does have this (apparently undocumented) feature. So it's possible that some other handsets do as well (though not the LG 440g).

What about Smartphones?

Most smart phones also
do not appear to have this feature, although I did find one, the HTC One to be precise, which does have it. That means that it is possible to implement this on the Android OS.